Cloud AltitudeMaximum altitude for cloudrise is reached after ~ 4min. RATE OF RISE OF THERADIOACTIVE CLOUD FROM a I-MEGATON AIRBURSTHeight Time Rate of Rise(miles) (min) (mph) 2.0 0.3 330 3.0 40.7 270 4.0 61.1 220 5.0 102.5 140 6.0 123.8 27

Cloud height & cloud radiusdepend on the magnitude ofthe explosion, increase ofboth radius & height scaleswith explosion yield.

Operation Greenhouse

Operation Plumbbob

Atmospheric tests at low & high altitude

High Altitude Air Blast: fireball > 100,000 ft (>3000m)

Low Altitude Air Blast:fireball < 100,000 ft (without touching ground)

Surface Blast:fireball in touch with surface

Subsurface Blast:Underwater burst

Underground Blastunderground conditions

Low Altitude Tests

YESO, 3000kT; B52 drop free fall to 8300ftr = 2705 ft ≈ 900 m

SWANEE, 97kT; B52 parachute fall 3000ftr = 685 ft ≈ 228 m

Pressure surge downward, shockfront emission: Fireball evolutionR = 110 W0.4 [ft] (W = yield in kT of TNT)

r = 110·W0.4 = 694 ft ≈ 230 m

Development of the Airburst

1.2 s: Shock-front re-bounce

0.5 s: Shock-front fireball evolution

3 s: double shock-front upwards motion

10 s-30 s: Surge and stem evolution

Model

225 kT GEORGE test Opertion Greenhouse

10 ms

20 ms

30 ms

Altitude Test Delivery Systems

Early planning and developmentsGermany invested successfully in long range missile systems during WW IIIn the believe to invest into a crucial weapon for final victory. However, the

limitations in transport capabilities were too severe to allow sufficient load on explosive material. The production was limited, 1000 V2 missiles were employed, but the final impact on the war development was negligible.

ICBM developmentsAfter the Soviet success with Sputnik, US sought for development of Intercontinental Ballistic Missiles (ICBM) to complement the bomber fleet and address the new challenge. US military success was limited until NASA took over the missile development.

Success at last!

e.g. Dominic tests on the Christmas Island 1962shortly before test ban in 1963;

Main purpose is the developmentof and EM pulse over a large area

High Altitude tests

The electromagnetic pulse (EMP) from these tests sent power line surges through Oahu, knocking out street lighting, blowing fuses and circuit

breakers, and triggering burglar alarms.

STARFISH PRIME, 1962; 1450 kTThor Missile airburst; 248 miles,

KINGFISH, 1962; 1000 kTThor Missile Airburst; 320,000 Feet

Long distance observation

The blast from Starfish was seen at 800 miles distance from Honolulu, Hawaii. OriginatedAuroral light phenomena through -radiationinduced excitation effects in atmosphere.

prior to blast during blast post-blast Auroral light

High Altitude Tests

Atmospheric Effects